A variety of food items and biologicals are process in such a manner that they are intended to remain in a frozen condition until ready for use. Thawing, whether during transportation, storage or display, may affect the flavor, nutritional value, appearance, texture and possibly the healthful condition of food items. The viability of some biologicals can be at stake when continuous frozen conditions are not maintained. Through use of this invention, those involved in the distribution and/or final use of frozen products will have the ability to realize whether thawing has occurred.